Spring stressing device



July 7, 1959 A. F. GATTIKER, JR., ETAL 3,

SPRING STRESSING DEVICE Filed Dec. 27, 1955 2 Sheets-Sheet v1 3 l6 4 F/G 2 INVENTORS I THEIR ATTORNEY y 1959 A- F. GATTIKER, JR. ETAL 2,893,719

SPRING STRESSING DEVICE Filed Dec. 27, 1955 2 Sheets-Sheet 2 ALBERTF GATT/KE/ZJR HAROLD 6 REYNOLDS THEIR ATTORN'EY United States G S RES LING E V CE Application, December 27, 1955 Serial No. 555,395 4 Claims. c1. 267-1) This invention relates to a spring tensioning deviceyfor springs, and more particularly to a device for torsionally stressing springs.

One object of this invention is to provide a relatively simple and inexpensive device for applying a torsional or on pr ngs- Another object of this invention is to provide a device by which springs may be quickly and accurately stressed. Further-objects will b rne apparent from the following pec fi at onand a companyi g drawing i which Figure 1 is a top view, partially in section, of the spring stressing device with a spring mounted therein,

Fig. 2 is a side view of the device in longitudinal section also showing the spring clamped in position,

Fig. 3 is a cross sectional view taken through Fig. 2 along the line 3-3 looking in the direction of the arrows, and

Fig. 4 is an end view of the device taken of Fig. 2 along the line 4-4 looking in the direction of the arrows.

Referring to the drawings, the spring stressing device includes a clamp 12 for fixedly holding one end of a spring assembly 14 including the spring 49 to be stressed. The opposite end portion of the spring assembly 14 is engaged in a socket 20 of an arm 18 rotatably supported by a mounting 16. A bolt 22 is threadedly connected to an end portion of arm 18 to rotate it against the resistance of the spring 49 of the assembly.

The clamp 12 includes a movable upper section 24 and a fixed lower section 26 secured to a base 28 by means of bolts 30 (only one of which is shown). The lower section 26 is generally rectangular in shape and has a semi-cylindrical opening 33 in the upper portion thereof. The surface of the opening 33 contains a number of grooves 32 the axes of which are, in general, parallel to the axis of the opening 33.

The upper section 24 of clamp 12 is similar in shape to the lower section 26 but has a smooth semi-cylindrical opening 34 in the lower portion thereof so located that when the upper section 24 is placed upon the lower section 26 the openings 33 and 34 form a circular shaped opening. One end portion of the upper section 24 is hinged to an end portion of the lower section 26 by means of a link 36 and pins 38 so that the upper sec tion may be swung easily away from lower section. An eye-bolt 40 hinged to the opposite end portion of the lower section 26 by means of a pin 42 is adapted to fit into a slot 44 in the end portion of the upper section 24. The end portion of the eye-bolt 40 which extends through the lot 44 is threaded to accommodate a wing nut 46 which, when upper section 24 is in place, may be rotated to exert pressure upon an upper surface thereof.

Secured on the base 28 in fixed space relation relative to the clamp 12 is the mounting 16. The arm 18 rotatably secured to the mounting 16 is adapted to engage and rotate an end portion of the spring assembly 14 against the springs torsional resistance. In furtherance to this end, an end portion of the arm 18 has tent ice

' 2. a equal-reshaped socket 20, therethrough adapted to receive the square end 47 on the spring 49. The other end portion of the, rotatable arm; 18 is slotted and contains a pivot 48 throughwhichtheradjusting bolt 22 is threaded, The lower end Qfzi-the :bolt' 22 is adapted to fit .into a depression 50 in the upper surface of base 28 while the upper end-portionhaseaperpendicular handle 52 to pernit the bolt 221.10 be turned by 'hand. When the bolt 22 is turned, it exerts force through the pivot 48 against the end portion of .thearrn 18 turning it against the resistance of the spring element. 14.-

Thespring assembly 14'shown by way of example and an application of which-is shown in US. Patent #.2,,822,677 includes thespring 49 and a cylindrical casing '51. into which: the spring 49 extends and has a socket connection. therewith atone .end portion of the casing, The outer-surface .of the opposite end portion of the casing 5 ;1'has splines 53ithereon, the axes of which are parallel to: the axis of the casing, and adapted to be engaged zin groouesf32 inithe clamp 12. The spring 49 has .an .elon'gatedshape and, ingeneral, a cruciform cross section. The-endtportionsof: the spring 49 extending from:andxadjacentato-theribbed end of the casing 51 .CQIlSlStSaOf'. a-cylindnicalvrsplined' section 56 followed by the substantially square section 47 which is adapted to be engaged by the arm socket 20.

A locking element, or sleeve, 58 is provided to lock the spring 49 to casing 51 after the spring has been properly tensioned. The locking sleeve 58 is, in general, tubular in shape with a central passage 60 adapted to fit over the end portion of the casing 51 and the splined portion of the spring 49. In furtherance to this end, one portion of the passage 60 is splined, as at 62, to engage the casing splines 53 while an adjacent portion 64 contains splines adapted to engage the spring splines 56. When the sleeve 58 is in the locked position (see Fig. l), the locking device splines 64 and 62 will engage splines 56 and casing splines 53, respectively, locking the spring 49 and casing 51 against relative rotational movement.

In operation of the spring tensioning device and assum ing that the spring 49 is assembled in the casing 51, the square 47 of spring 49 is inserted in the socket 20 of the rotatable arm 18. The spring casing 51 is then placed in the semicircular opening 33 of lower section 26 so that the casing splines 53 are engaged by the grooves 32. The upper section 24 is placed upon lower section 26 so that the surface of the semi-circular opening 34 rests upon casing 51. The eye-bolt 40 is then swung into slot 44 of upper section 24 and the wing nut 46 tightened until the casing 51 is securely held between the sections 24 and 26.

The locking sleeve is then positioned as shown in Fig. 2 and the screw turned to rotate the arm 18 and hence rotate one end 47 of the spring 49 relative to the opposite end thereof. When the desired tension of spring 49 has been obtained, the locking sleeve is moved to the position shown in Fig. 1 so as to engage the spring splines 56 and casing splines 53. Bolt 40 is then loosened, wing nut 46 unscrewed and the casing 51 containing the stressed spring 49 can be removed from the device.

While we have shown and described a specific form of our invention, it is to be understood that various changes and modifications may be made without departing from the spirit of the invention as set forth in the appended claims.

We claim:

1. A device for applying torsional force to a spring assembly including a spring, comprising clamping means adapted to hold one end portion of the spring against rotation in one direction, a mounting held in fixed relation with respect to said clamping means, a member ro to apply a torsional force thereto. ll

tatably mounted on said mounting for rotation in said:

direction and adapted to engage the opposite end portion of said spring for rotation, and-fine adjusting means operatively connected with said member and said mounting and manually adjustable for rotating said member against the resistanceof said spring to apply a torsional force thereto. i v

2. A device for applying torsional force to a spring assembly including a spring, comprising'a base, clamping means fixed to the base and-adapted to grip a portion of the spring assembly to hold one end of the spring against rotation, a mounting secured to the base, amember rotatably mounted on said mounting and adapted to engage the opposite end portion of said spring for rotation, and screw means associated with the base having a threaded pivoted connection-iavith' saidmember for rotating the member against the resistance of said spring 3. A device for applyingtorsionall-force'toa 'spring assembly including a cylindrical easing into which a spring extends having one end :portion thereof connected to said casing to preventrelative rotation between said one end portion and the casing, comprising a base, clamping means secured to. the base. andincluding a lower section and an upperi section hinged at one end and having screw means at the opposite end and operable to move said upper section toward said lower section to clamp the casing between said sections, a member rotatably mounted on the base and adapted to engage the opposite end portion of spring for rotation, and screw means having a threaded pivoted connection with the member and cooperating with said base for rotating said member against the resistance of said spring to apply a torsional force thereto.

4. A device for applying torsional force to a spring assembly including a casing with a splined outer portion and into which a spring extends having one end portion thereof secured to said casing to prevent relative rotation between said one end portion and said casing, comprising a base, clamping means secured to the base having a circular opening with a grooved portion for engaging the splined portion of said casing to prevent relative rotation therebetween, a member rotatably mounted on said base and held in fixed spaced relation with respect to said clamping means and adapted to engage the opposite end portion of said spring for rotation, and screw means cooperating with the base for rotating said member against the resistance of said spring to applya torsional force thereto. e 1

References Cited in the file of this patent UNITED STATES PATENTS Kane Mar. 27, 

